The Grain to Tilbury project involves replacing the existing 1960s Thames Cable Tunnel beneath the River Thames between Tilbury and Gravesend, which currently houses 400 kilovolt (kV) transmission cables.
The tunnel has reached the end of its operational life, so our project will include:
- construction of a new 2.2 km tunnel under the Thames
- installation of new high-voltage cabling
- building two headhouses at either end of the tunnel for access and connection to the wider network
- reconductoring the existing overhead line routes between Kingsnorth, Grain and Tilbury
This upgrade is critical to ensuring more secure, cleaner, home-grown energy from more affordable sources flows through the network.
The Grain to Tilbury project forms part of a wider suite of infrastructure upgrades and reinforcements planned by National Grid as part of The Great Grid Upgrade, the largest overhaul of the electricity grid in generations.
The project received full planning approval for the Grain to Tilbury project from Thurrock Council in Essex and Gravesham Borough Council in Kent, a key milestone in strengthening the UK’s energy network. Our applications can be viewed here: 23/01502/FUL (Thurrock) and 20231313 (Gravesham).
Grain to Tilbury construction
Find out more about our project and the works that will be required to replace the Thames Cable Tunnel.
Where we are now
Following approval of our applications by Thurrock and Gravesham Councils in early 2025, our work to deliver the Grain to Tilbury project has begun.
In Summer 2025, pre-commencement enabling works took place on both sides of the river, with staff offices, welfare and the sites set up.
In October 2025, the Vertical Shaft Sinking Machine (VSM) was delivered, built and has now been turned on, with work underway to construct the tunnel shaft.
On the Gravesend side, pre-commencement works are ongoing, with the cycle path shortly due for closure to facilitate for works to begin on-site. A diversion will be in place, with more details available here shortly.
We are also undertaking pre-commencement works for the reconductoring of the overhead lines (OHL), which includes trial boreholes ahead of works beginning next year.
Accessibility
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Contact us
For general enquiries or to register for project updates, please use our contact form below, or contact us by:
Phone: 020 3398 1599
Opening hours: 9:00am – 5:30pm
Freepost: FREEPOST GRAIN TO TILBURY PROJECT
The Great Grid Upgrade
The Great Grid Upgrade is the largest overhaul of the electricity grid in generations. Our infrastructure projects across England and Wales are helping to connect more renewable energy to your homes and businesses.